As is well known, a bowler purchases a new bowling ball in a form that is free from finger holes. In the usual case, the ball is sold with an index mark which is generally intended to be located centrally of the finger holes. Holes are drilled about the index mark, typically for receipt of the middle finger and the ring finger on one side of the index mark and a hole for the thumb on the opposite side thereof.
The holes may be bored to various diameters to fit the finger size of the bowler. Typically, thumb hole and finger hole diameters will range from 5/8 of an inch to 13/32 of an inch.
Other dimensions of concern include the "span" and the "bridge".
Span is the distance between the near edges of the thumb hole and either of the finger holes, whereas bridge is the distance between the near edges of the two finger holes. "Pitch" is still another parameter. Pitch is the distance between the center line of a finger or thumb hole and a parallel radius of the ball. As can be readily imagined, with the number of variables involved, drilling the finger holes in a bowling ball is not a job to be relegated to the ordinary man on the street.
Generally, then, the balls are purchased at stores that specialize in bowling goods and/or bowling "pro" shops where there is sufficient traffic in bowling ball sales to justify the presence of a ball drilling apparatus as well as an experienced operator for the drilling apparatus. In addition, it is necessary that there be a person in attendance who is knowledgeable in fitting a ball to a bowler so that the proper hole diameters, span, pitch and bridge may be determined to set the parameters for the drilling operation.
It is believed that the foregoing situation has deterred many bowlers from buying their own balls, the bowlers relying instead on so called "house" balls maintained in most bowling establishments for use by patrons who do not own their own balls.
The problem may be compounded because many such establishments are relatively small and do not have the personnel available to fit the ball and then drill it during a single visit by the patron. Frequently, the ball will be fitted during regular store hours, but will not be drilled until after store hours, necessitating a return trip by the purchaser to pick-up the drilled ball.
And, frequenting such a store specializing in bowling goods to make the purchase of a bowling ball is a less likely occurrence than a person frequenting a mass merchandiser, discount warehouse or the like. Consequently, the purchase of a bowling ball by many is put off, or does not occur at all because of this factor.
One of the parameters of concern in fitting a bowling ball is the size or diameter of the finger and thumb holes that must drilled therein. In our co-pending application Ser. No. 08/336,143, filed Nov. 14, 1994, the details of which are herein incorporated by reference, there is disclosed a system whereby the bowling ball is drilled with holes of constant diameter and inserts having a hole of the diameter that fits the bowler best inserted in the constant diameter holes to complete the fitting process. While this system is satisfactory for its intended purpose, it does require the fitting of inserts to a drilled bowling ball, as well as the provision of a supply of the inserts in all sizes so that a bowler can be properly fitted. If a complete inventory of inserts is not maintained at all times, then there is always the risk that a bowler cannot be properly fitted because an insert of the proper size is not on hand.
To avoid this problem, our commonly assigned application Ser. No. 08/380,077, filed Jan. 30, 1995, the details of which are herein incorporated by reference, discloses a means whereby the fitting apparatus provides electrical signals indicative of the size of each finger hole and thumb hole to be drilled in a ball and the drilling part of the apparatus responds accordingly. As disclosed in application Ser. No. 08/380,077, a drill bit may be rotated about its axis or may be revolved in an orbital fashion about the axis of rotation of a drive motor or the like. The diameter of the hole being drilled is determined by the spacing between the orbital path of movement of the drill bit and the axis of rotation of the drive motor.
According to application Ser. No. 08/380,077, a carriage mounting the drive motor and the bit may be moved away from a ball support and into engagement with an adjustment mechanism. The adjusting mechanism receives complete size information from the fitting part of the apparatus and adjusts the diameter of the orbital path of the bit to achieve the desired hole diameter. Once this adjustment is made, the carriage is then moved towards the ball support advancing the bit and drive source therewith to drill the hole.
Since a typical bowling ball will be drilled with three holes, one for each of two fingers and one for the thumb, and because not all holes will have the same size, it is necessary that the system of application Ser. No. 08/380,077 be adjusted after each hole is drilled by stopping the bit drive and moving the carriage away from the ball support to engage the adjusting mechanism, and perform the necessary adjustment is then made before the next hole can be drilled. This, of course, is somewhat time consuming and in the mass merchandising environment that is envisioned for the apparatus, undesirable because purchasers are anxious to complete their purchase and move on.
The present invention is directed to overcoming one or more of the above problems.